Xbox 360 SMC Error: 0020

ERROR_GPU_RST_DONE

GPU_RST_DONE signal missing after seqUnReset time passed

This means the GPU did not assert the GPU_RST_DONE signal within the allotted time

  1. GPU Reset Done
    • This signal must be checked quickly, immediately after powering on
    • Check if GPU_RST_DONE is high (3.3V):
      • Phat: FT2P13
      • Trinity: FT3R16
      • Corona: FT3T2
    • If signal is missing, proceed to the next step
    • Check 1K Ohm resistor:
      • Phat: R3P7
      • Trinity: R3R19
      • Corona: R3E6
    • Check 10K Ohm pull-down resistor:
      • Phat: R3P6
      • Trinity: R3R20
      • Corona: R3E7
    • If the signal is present, resistors are in range, replace Southbridge:
      • Phat: U2C1
      • Slim: U3D1

  2. GPU Reset
    • GPU_RST_N must go high in order for the GPU to run
    • It is controlled by the Southbridge
    • Check that GPU_RST_N goes high (1.2-1.8V):
      • Phat: FT2P14
      • Slim: FT3R17
    • If missing signal, replace Southbridge:
      • Phat: U2C1
      • Slim: U3D1

  3. GPU Clock
    • Check that ANA_CLK_OE goes high (3.3V):
      • Phat: FT2P4
      • Trinity: FT3R13
      • Corona: Skip this step, signal not present
      • If missing signal, replace Southbridge:
        • Phat: U2C1
        • Slim: U3D1
    • Check junction between the sets of 33 and 49.9 Ohm resistors for proper 100 MHz differential clock
    • If bad/missing signal, check the values of the resistors as follows:
      • Phat:
        • Check R3C7 and R3C8: 33 Ohms
        • Check R3C15 and R3C16: 49.9 Ohms
      • Trinity:
        • Check R3C3 and R3C4: 33 Ohms
        • Check R3C7 and R3C8: 49.9 Ohms
      • Corona:
        • Check R3D10 and R3D12: 33 Ohms
        • Check R3D11 and R3D13: 49.9 Ohms
    • If still bad/missing clock signal, replace clockgen chip:
      • Xenon: Cypress CY28517 U3B4
      • Zephyr, Falcon, Jasper: HANA U4C2
      • Trinity: HANA U3B1
      • Corona: Southbridge U3D1

  4. GPU
    • If all else fails, GPU is bad and must be replaced:
      • Phat: U4D1
      • Slim: U5E1